Cold start nailing sound - PeachParts Mercedes-Benz Forum

psaboic · #1 09-14-2010, 10:00 AM

HI folks,

Now that the weather is getting colder I have started to notice an issue with my 83 300D. When I first start it in the morning or after sitting for a couple of days, it will fire right up and idle and sound normal. Then after about 5 seconds, it will start to make a nailing, louder clatter sound from one or two cylinders. This will keep up until the temp needle starts to rise off the cold peg, then it will purr like a kitten.

Oil pressure is normal, and I just checked all the glow plugs and glow plug relay and strip fuse, and there are no problems there. I also did a full diesel purge about 3000 miles ago.

What do you think? Crappy fuel, injectors, or ??? It has 235K on it and I have no idea if the injectors have ever been changed. Living out in East Jesus Nowhere, I hope to find an easy solution to the problem.....if it even is a big problem

Biodiesel300TD · #2 09-14-2010, 10:13 AM

Nailing is caused by poor spray or early spray of the injectors, and is a sign of worn out injectors. One thing you can try, is to run a can of two of Diesel Purge straight through the fuel system. This will clean out build up and gunk in the IP and injectors. This might solve the problem. If not the next step is to pull the injectors and have them tested. You'll want to test the spray pattern as well as the pop pressure. Then you can decide if it's time for new nozzles. If you have 235k on the original set it's probably time for some new ones. They say to change them every 100k.

#3 09-14-2010, 10:13 AM

I would start with checking the glow plugs to make sure they are all functioning; then I would think about the injectors. Replacing my injectors solved a similar issue and inproved cold engine performance noticeably.

psaboic · #4 09-14-2010, 10:36 PM

Glow plug system checks out just fine.

Is there a recommended place on-line that sells injectors ready to go? (no assembly or testing needed) Basically just pull the old ones and put the new ones in? I want to keep it fairly simple.

Thanks,

Glenn

Biodiesel300TD · #5 09-14-2010, 10:43 PM

See the Buy Parts tab at the top of the page, and look up injectors. Despite all the Bosch injectors are crap thread, I bought some reman Bosch injectors and put them in without touching them and my 240 idles perfect, so they are all balanced enough that the engine purrs along great.

barry123400 · #6 09-15-2010, 10:02 AM

Quote:

Originally Posted by psaboic

Glow plug system checks out just fine.

Is there a recommended place on-line that sells injectors ready to go? (no assembly or testing needed) Basically just pull the old ones and put the new ones in? I want to keep it fairly simple.

Thanks,

Glenn

I would tend to check the injectors somewhere before arbitrarily ordering new. There is both a possibility they were done some time ago and only one or two need the attention now with the others in good condition. For all I know it might be more economical to have yours checked and recondition as needed. On the otherhand they could be on there last legs so to speak. You just do not know without getting them tested. One of our site members provides this service still I believe.

Diesel911 · #7 09-15-2010, 10:45 AM

Quote:

Originally Posted by psaboic

Glow plug system checks out just fine.

Is there a recommended place on-line that sells injectors ready to go? (no assembly or testing needed) Basically just pull the old ones and put the new ones in? I want to keep it fairly simple.

Thanks,

Glenn

The Member in post number 10 will rebuild your set with Made In Germany Monark Nozzles. PM him for the cost details.
No matter who you get them from on the internet you will be paying shipping to get them and shipping to return so that you can recover your Core Charge.
http://www.peachparts.com/shopforum/showthread.php?p=2544379#post2544379
If you need them done faster C Sean Watts sells the Monark Spray Nozzles and you can find a local shop to do the Rebuild for you.

You will also note in the above thread that I dislike one of the features on the stock Spray Bosch Nozzles even if they were not made in India.

I have the Monark Spray Nozzles in my Mercedes and even put them in my Volvo Diesel to good effect.

Each area is different but in my area a use Injector that you pull fromt he Junk Yard is $5 each. You could pull some Injectors and send that set off to C Sean Watts for rebuild. (I have not read that he has any exchange sets for sale but you could ask him.)

charmalu · #8 09-15-2010, 10:49 PM

BGKAST is near where you live. he was doing Fuel Injectors a while back. maybe send him a PM.

Charlie

#9 09-15-2010, 11:06 PM

Quote:

Originally Posted by Biodiesel300TD

See the Buy Parts tab at the top of the page, and look up injectors. Despite all the Bosch injectors are crap thread, I bought some reman Bosch injectors and put them in without touching them and my 240 idles perfect, so they are all balanced enough that the engine purrs along great.

I just had my indy throw in a set of rebuilt injectors as well. I don't know/care where he sourced them, they have been working fine for about 50K miles now. They are fairly cheap and easy to install, no need to turn this into a science project.